hwdy do
my Eb seems to be having some idle problems when the car is in D and the AC is on. it idles around 200-250 or so. also when i give it a bootful then back off it drops to just about 0 then comes back up.
is there a base idle u ca set cause i think this is way too low and i dont want it to stall on the road (hehe stalling an auto)

cheers
Regie

yeh i got da same problem with my eb bit curious as to wat it might be, possibly might just need a tune up im not sure either

im thinking it may be the ISC.
is it that that bumps up the idle when u turn the AC on? etc etc.
can u clean it or is it better to buy a new one. how much if anyone knows??

cheers
Regie

do u no how hard it is 2 read posts dat r typt lik dis??????

To check the base idle you need to,

Drive the car until its at operating temp, then stop motor
Disconect the ISC wiring connector
Start motor and using a tacho check base idle speed.
Adjust base idle screw until idle is around 500-600rpm.

cool is the ISC the tubular thing that sits ontop of the throttle body? im gunna have a play around tommorow

Edit: All fixed. they base idle was way out. when i disconnected the ISC the car wouldnt even idle it just kept stalling. piece of piss to fix i shoulda done it ages ago hehe

Im having the same problem with my au when im driving it is fine when its ideling its fine, turn on the air cond at idle and when the compressor kicks in it drops the idle and nearly stalls or does stall, and if im sitting at lights and then go to take off 7/10 times it stalls. What the f#$k is wrong with it ? Does anyone have a clue ?
BTW its petrol/gas and doesn't seem to do it on petrol.

sorry not sure what the isc is. Can you post some pics of it and of what to do as im having this same problem and yeah it only happens on gas aswell

This is some new information I've found. Since my Flat spots ago go thread nobody answered to

Some may be able to fix their idle problem turning up the screw on the ISC. And even then some will find that turning on the air-con doesn't actually increase idle or stabilize it, but drops it 200RPM. And in this instance, sitting at lights in drive with air-con will exhibit a serious vibration into the C**k, as happens when the idles too low.
I always thought there was some kind of relay that worked with the ISC, to maintain Idle speed during air-con use.
But I found out it is in fact the ECU that controls the idle speed when air-con is activated. And this can screw up for some reason, and apparently then needs replacing.
I was told by one wrecker that this was the case (didn't believe him then) and that a lot of our cars have the same problem.

Why is this the case I wonder?
What is with the ECU that it should start to do this over time?


** The ISC is on top of the throttle body half way along the big plenum chamber. It has the accelerator/cruise control cables going to it. It has a small black plastic knob on the front of it (still don't know what it's for). And on the firewall side of the ISC is a black plastic plug. The ISC is bolted onto the throttle body by 2 bolts.

If you have some appropriate throttle body cleaner like a Nulon spray, it's good to unplug the ISC, undo the bolts, carefully lift it away. And spray the cleaner inside the ISC, to remove carbon, and to clean the top of the throttle body. While your at it, unplug the intake tubing to throttle body, follow directions on the can and clean the throttle body itself.

The best practice guide to setting the idle speed is as follows:

This will require the use of a strand of wire with alligator clips on each end like those from Tandy.

1. Run car to operating temp. Stop car. Remove fuse box lid under the fuel cap release button. See the white connector at the top of the fuses that looks like a printer connector or something. Using your wire, very carefully connect one metal alligator clip to the 1st pin on the top row. And the other clip to the 1st pin on the second row. Obviously the metal clips can't come into contact with each other.

2. Unplug the plug from the ISC. It's a good idea to place a .75mm feeler
gauge between throttle lever stop tab (tab the acc cable connected to) and ISC screw. You can use a credit card instead. Should be .75mm though

3. Start engine. The engine revs will rise to between 1300 to 1600rpm. Thats the diagnostic mode you've placed it into with the wire and connectors.
Wait a minute for the idle to return to normal speed. Do not touch the pedal.
If the idle shows it to be between 600 - 800 rpm. No adjustment is required. I find that if it is already around 600 to 650, and problems have persisted, then make it around 850 rpm.

4. If adjustment is required adjust the screw to between 750 to 850 rpm (clock wise I think?)

5. Ignition off. Remove wire/clips from connector and attach fuse box lid
plug the ISC wiring connector back in. Oh, and remove that credit card too, if you used one.

That should be it.

my mates car was doing this and the problem was he was low on water in his raiator and it was blocked. this lead tofluctating levels of water passing through the bottom radiator hose and over the senser this made his cars idol surge. dont know if its the same sort of thing but that is what his problem was